WordPress paginated posts + "Full Page" link. Thx to: http://wordpress.org/support/topic/link-to-show-entire-paginated-post-on-one-page?replies=4#post-1483026

functions.php

<?php
/**
 * Allow parameters to be passed in the URL
*/
add_filter('query_vars', 'parameter_queryvars' );
function parameter_queryvars( $qvars ) {
    $qvars[] = 'full'; // This is the parameter for the url: yourblog.com/your-post/?full=1
    return $qvars;
}

/**
 * Custom paginated posts links
*/
if ( ! function_exists( 'manoz_content_nav' ) ):
    function manoz_content_nav() {
        $paginated = wp_link_pages(
            array(
                'before' => '<div class="page-links"> <span>Pages:</span>',
                'after' => '</div>',
                'next_or_number' => 'number',
                'echo' => '0'
            )
        );

        $paginated = str_replace(
            '</div>',
            '<a href="'.get_permalink().'?full=1"> Full post</a></div>',
            $paginated
        );
        echo $paginated;
    }
endif; // manoz_content_nav

?>

single.php

<?php
    /* Replace <?php the_content(''); ?> with this */
    global $wp_query;
    if (isset($wp_query->query_vars['full'])) { $n_pagination = $wp_query->query_vars['full']; };
        if($n_pagination) { 
            // If post is paginated, echo the_content and the nav links
            echo apply_filters('the_content',$post->post_content);
            $page=$numpages+1;
        } else { 
            // If post is NOT paginated, just echo the_content
            the_content('');
        };

    manoz_content_nav(); 
?>